Contest: luck is with you

In the following matrix of 17 x 17 (rows: 1 to 17, columns: A to Q, 17 because it's prime number), in one of the cells is hidden the prize that has corresponded to me in the infographics contest (GameForge coupon of 10 euros) .

Any user or member of the team (except Valent) can post in this thread maximum once a day by sending coordinates (for example 8:J, row 8, column J). Who hits the cell where the prize is hidden takes it away.

Each day I will mark with an X (no reward) the coordinates of the cells that have been sent.

To avoid suspicion, I sent a private message to Valent with the coordinates of the prize. Valent also knows the coupon code, and you will have to trust my promise that I have not used this coupon.